Repeating coil.



H. D. CURRIER.

REPEATING COIL. APPLICATION FILED Arnfm'rsu.

' JZ-ZUEHYE E STATES PATENT OFFICE.

manic n. connmn, or ceramic, ILLINOIS, ASSIGNdR 'ro KELLOGG swmcnnonmi. nun sunny com an on cnrcaoo, rumors, A conronn'rzon or ILLINOIS.

REPEATING COIL.

Specification ofLetters Patent.

Patented Sept. 17, 1918.

Application filed April 9, 1814. Serial No. 830,58!

To all whom it may concern:

Be it known that I, HIRAM D. Gunmen, a

citizen of the United States of America, re-

" useful Improvements in Repeating Coils, of

which the following is a specification.

My. invention relates to repeating coils or telephone transformers for use in cord C11- cuitsof telephone switchbo'ard s. .It is the object of iny invention to produce an im proved device of the class described, .which will embody desirable features and ad-van' tages all in a simple, eflicien't and econou'lical manner, and to this object and such other objects as mayiappear, my inventiofl'consists in the novel details of construction, garts and combinations of parts hereinafter escribed and-as particular y pointed'out in the appended claims. A feature of iny invention is a U-shaped core permitting of easi mountingof the windings thereon in sucQrelation to each other .as to result in .eflioient-disposition of the windings in relation to the core. Two spools each hsrving .an insideand outside winding concentrically related are placed over either arm of the U- shaped core. The inside winding of one spool is serially connected to the outside Winding of the other spool and these two windings serve to form one half of the transformer circuit. The other windings ofthefspools are connected in like manner and form the other half of the transformer circuit.

. The advantage in using a U-shaped core isin bringing the two poles of the core in such relation to each other that the lines of force'set up in the core in passing from one polefto the other are. deflected away from the windings and thus reduce the neutra1izing 'efl'ect resultant'from such leakage when a straight core is used. The U-shaped core I also adds to thecompactness of 'thecoil.

' in. the accompanying drawing, in which like Referring-to my invention-as illustrated characters denotelikeparts and in which Figure" 1 is afront elevation of the re peating coil with the housing broken away toshow one spool of thecoil;

Fig.2 is a t pview of the repeating c011 showing the terminals;

coil; a

. Fig. 4 is. a esd i Fig. 2;

.1 (Fig. 2), the said terminall being con- Fig', '3 is abottom View ofthe repeating Fig. 5 is a sectional view on the line5, 5 of Fig. 6 is a view of the repeating coil with the bottom plate removed;

F 1g. 7 is a diagrammatic view of the coil showing the windings upon the core and also showing connections of the four windings.

Referring now more in detail to my invention as illustrated, it comprises a Ll-sha d' core A preferably madeof small gage her way iron which is wrap ed with tape to help keep its cylindrical t drm. The core is made of small Norway iron to reduce the hysteresis loss to a minimum but this finely dividing of the core to reduce hysteresis loss is old in the art but the forming of the core into a U-shape I consider new. as this brings the poles of the core in close proximity and tins tends to prevent the lines of force from separating from each other and consequently the lines of force are deflected to-the opposite end of the corcpreventing the back leakage through the windings which would be the case if the core were straight; It is desirableto'have an air. epin a telephone transformer and thus re uce the line constant of the coil providing-this can be done without introducing leakage through the windings. y

The coil is made up of two spools B and 0 each spool having two windings namely an outside winding D and an inside winding E on spool B and an inside winding F and an outside winding G on spool C, said windings being suitably insulated from each other by wrappings of oiled silk. As tothe connection of the windings, by; referring to Fig. 7,

it may be seen thatthe outside winding D has its inside end 9 connected to the terminal nected 'to the tip conductor 10 of the trans: Initting side of the repeating coil when used on a metallic line. The outsidecndll-of the winding D is connected to ,the -.o1.\tsi de end 12 of the inside winding F at terminal 7 .100 (Fig. 2). The inside end' 13 of the insidewlnding E is connectedto the terminal 3' (Fig; 2) the said terminal 3 being'connected to the tip condu'cter 14-of the receiving side .of the repeating coil when used on a metallic 105 line. The outside end 15 of the inside winding E is connected to the outside end-16 of the outside, winding G at terminal. 5.5.(Fi 2). The inside end 11 of the outside win ing G is connectedto the terminalifi '(F ig. m

. inside winding F 1s connected to the terminal 8 ('Fig. 2), the said terminal 8 being connected to the sleeve conductor 20 of the transmitting side of the repeating coil. The outside end 12 of the inside winding F is connected tothe outside end 11 of the outside Winding D at terminal 2 (Fig. 2). The outside end 16 of the outside winding G is connected to the outside end 15 of the inside winding E at terminal 4, Fig. 2. This particular manner of connecting is necessary to the operation of the coil and is an important.

element of my invention.

The windings are connected so that the inside Winding of one spool is connected to the outside winding of the opposite spool, and these two windings form one half of the transformer circuit. This arrangement permits each half of the transformer circuit being in the same dimensional relation to the core. With the arrangement as described above, which results in each halfof the trans- ;former circuit being in the same relation to the core, the. current induced from one half of the transfo mer to the other reacts on the core to the same degree as the impressed current with the result that we obtain transformation with the minimum loss.

The repeating coil is placed in a rectangular shaped housing 21, the said'housing being preferably made of cast iron and the reason for in this housing is to eliminate cross talk. The housing also forms a dust proof containing member for the said repeating coil and is of a shape and size amount of space when being mounted. The flanges 22 extend downwardly from the lower extremities of the ends of the housing and are integral with the same. The said flanges 22 are drilled and tapped to receive the screws 24 which clamp the back plate or cover 25 to the housing 21. The cover 25 when clamped down tightly to the housing by means of the screws 24 bears against the ends of the U-shaped core A and formsa closed magnetic circuit for the core. The plate 25 in being clamped down to the housing 21 aids asa compression means against the ends of the Ushaped core to hold the said core and winding in theihousing against said movement -The terminal block 30 of any suitable insulation material is mounted on the opposite end of the housing 21 and is held in place on .rtl e housing by means of'the screws 31' Which pass through the housing and screw into the [said terminal block 30. The terminal clips 32 are suitably fastened to the terminal bl said clips being terminals for the winding of the four coils which are mounted on the placing the said repeating coil as to take only a small' 30 by means of the screws 33, the

tacting with the ends nal block and are soldered to the said terminals/ The terminals are numbered from 1 to 8 inclusive and aid in connecting the re peating coil when used in connection with the cord circuit of a telephone system,

I have shown the repeating coil in a mounted position in Fig. ing mounted on a rack 26 and held in place on the said'rack by the bolts-27. The bolts 27 pass through openings 28 of the flanges 22 and. openings 29 in the back plate 25.

Having described-my invention, what I' claim as new and desire to secure by Unif H States Letters Patent is:

1. In aztelephone repeating coil a U-shaped core having only four thereon two of said windings being inside windings and two outside windings with one inside winding connected to one outside winding forming one half of the transformer circuit and the other half of the transformer circuit formed with the other two windings connected in like manner and a member for completing the magnetic circuit of said core. v

2. In a telephone repeating coil a U-shaped core having two spools, a primary and a secondary winding mounted on each of said spools, the inside winding of'each spool be.- ingc'onnected to the outside winding of the other spool, and a member for completing the magnetic circuit of said core.

3. In a telephone irepeating coil 2. U -shaped plate secured to said housing, said plate acting as a compression means for said core to securely hold the core 1n place when the,

5, the repeating coil be- Y windings placed plate is secured to the housing and for completing the magnetic path of said U-shaped core.

5. In a telephone repeating coil, :1.' U'shaped core finely divided and havingfour windings placed thereon, a rectangular shaped housing, a bottom plate secured to said housing, said plate acting'as a'conipression means for said core to securely hold the core and windings in place when the plate is secured to the housing, and the'plate in conof the core forms a clomd magnetic circuit for .the said core.

6. A telephone repeating coil, a U-shaped core finely divided, two spools of two windingseach, two of said windings bein outside windings and two of them being inside windings, an inside winding and an outside winding concentricall related are mounted on each le of the fi-shaped core, a rectangular s aped housing for containing Said core and windin rs, a bottom plate, and

means adapted to camp the said bottom plate to the housing to form compression means for said U-shaped core for holding the core in place in the housing and to provide when secured to'said housing a closed inagn'etie path for said core.

7. In a transformer, a U-shaped core hawing four wii'idings placed thereon, two of tending out the extending through said grallv formed ears.

said windings being outside windings and two of said windings being inside windings,

one outside winding being connected to one inside winding and the other outside winding being connected to the other insidewinding, "a rectal'igular shaped housing for holdmg said core and. W!

ndings, a pair of ears formed lntegrallytl id housin and ex- .plate adapted to be secured to said housing for contacting with the odds of the core to form a closed magnetic circuit for said core,'and fastening means for holding said plate in position;

8. In a transformer, a discontinuous core having windings thereon, said windings comprising two primary and two secondary windings, one piimary and "one secondary winding being mounted on one portion of the core, and the other primary and second plate into said inteary windings being mounted upon the other portion of the core,a'n 1ron housing adapted to receive saidcore and windings, a cover plate for said housing adapted to be fas-' tened thereto to render said core continuous, and a pair of flanges formed integrally with sald housing, formingmounting means for said transformer.

9. In a transformer, a discontinuous core provided with a pair of primary and apair of secondary windings, one of said primary" and secondary windings being associated andmounted on one portionof the core, and the other primary and secondary Winding bein portion of the core, tl'lflSQCOXldmY windin being nearest the core in one instai'ice and the rimary winding being nearest the core in vt 1e 'othe instance, and meai'is for rendering the discoi'itinuous core continuous.

'10. In av transformer, a core having two spools connected at one end thereof, a pri mary and a secondary Winding forming a unit and adapted to be slid over one of the spools of said core, a similarly formed unit adapted to be placed. on the other spool of said core, the inside winding of each spool being connected to the outside winding of the other spool, and a member adapted to connectthe extended ends of said core to render the core magnetically continuous.

Signed by me at Chicago, in the county ence of two witnesses.

, 'HIRAM D. CURRIER. Witnesses:

. Win Bnnormnn, M. R.- Rocnronn.

associated and mounted on another,

10 of Cook and State of Illinois, in the pres- 

